Systems and methods for limb support

ABSTRACT

An orthotic device according to embodiments of the present invention includes a substantially rigid internal footbed with an external rocker bottom, two struts rigidly coupled to the footbed, a paddle coupled to each strut, each paddle having an inner surface configured to face a limb of a patient, and a strap system configured to interface with the paddles for tightening around the limb, the inner surfaces of the paddles including a plurality of protrusions configured to minimize sliding of the first and second paddles with respect to the limb or with respect to a cast applied to the limb. The orthotic device may include two or more support layers on the footbed, each layer having a support aperture larger than and at least partially overlapping the support aperture below.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/136,784 filed on Apr. 22, 2016 currently pending, which is acontinuation of U.S. patent application Ser. No. 14/951,170, filed onNov. 24, 2015, now U.S. Pat. No. 9,597,218, which is a continuation ofU.S. patent application Ser. No. 13/353,163, filed on Jan. 18, 2012, nowU.S. Pat. No. 9,226,843, issued on Jan. 5, 2016, which claims thebenefit of U.S. Provisional Patent Application Ser. No. 61/433,873,filed on Jan. 18, 2011. The contents of the above applications areincorporated herein by reference in their entireties for all purposes.

TECHNICAL FIELD

Embodiments of the present invention relate generally to limb orthotics,and more specifically to methods and devices for treating footulcerations and/or injuries to the plantar area of the foot.

BACKGROUND

Embodiments of the present invention relate generally to limboff-weighting or off-loading utilized for the treatment of ulcerationsand/or injuries to the plantar area of the foot. The development ofeffective means for treating foot sores or ulcerations, especiallydiabetic foot ulcerations, presents a significant medical challenge.Diabetic foot ulcers result in numerous lower extremity amputations peryear and account for more hospitalizations than any other singlecomplication of diabetes. A large percentage of diagnosed diabeticssuffer from foot ulcerations. In fact, foot ulcers are the leading causeof hospitalization of patients with diabetes and account for asignificant percentage of the costs related to diabetic care.

The burdens of such complications can also have a devastating effect onpatients and their families. Patients' quality of life can rapidlydecline leaving them unable to work, and dependent on family members tospend their time and resources caring for the patient. The problem iscompounded by the fact that many diabetics suffer from peripheralneuropathy and thus cannot feel pain. Because pain is often a primaryincentive for patient compliance, neuropathy patients frequently do notcomply with voluntary off-weighting or off-loading techniques, resultingin further deterioration of the wound and possibly leading to infection.Complicating matters further, the progressive disorder “CharcotNeuroarthropathy” significantly deforms the foot and the associatedulcerations, making off-weighting or off-loading measures even moredifficult.

One common cycle for this medical complication is chronic footulceration, infection, hospitalization, amputation and rehabilitation.This costly cascade of events need not take place because two-thirds ofdiabetic amputees do have an adequate blood supply to heal ulcerations.One significant factor for effective treatment can often be to offloadthe patient's weight from the ulcerated site to give the ulcers anopportunity to heal.

While some devices have been specifically designed to address the needto treat patients suffering plantar ulcers, it should also be noted thata number of related adjustable leg casts have also been developed. Suchcasts, however, are often designed primarily for fracture care ratherthan for treating plantar ulcers. Existing devices for treating plantarulcerations are often time-consuming to apply and/or relativelyexpensive, or result in sliding, movement or unintentional rearrangementof the device or its components shortly after application or duringambulation.

SUMMARY

Some embodiments of the invention address a particularly difficultdiabetic complication associated with plantar ulcerations related todiabetes: Charcot Neuroarthropathy. Charcot Neuroarthropathy is aprogressive condition affecting the foot and ankle characterized byjoint dislocations, pathologic fractures, and debilitating deformities.The progressive destruction of bone and soft tissues at weight-bearingjoints often causes significant disruption of the bony architecture.Those embodiments take into account such deformities, allow foroff-loading from the deformed and ulcerative site, and ultimatelyaddress one of the most debilitating causes of amputation. It should benoted that the FDA does not even allow wounds associated with CharcotNeuroarthropathy into diabetic foot clinical trials for evaluation asthey are considered too difficult to treat in terms of off-loading.

An orthotic device according to embodiments of the present inventionincludes a footbed with a substantially rigid internal footbed and anexternal rocker sole, a first strut rigidly coupled to the footbed, asecond strut rigidly coupled to the footbed, a first paddle coupled tothe first strut, the first paddle including a first inner surfaceadapted to face a limb of a patient, a second paddle coupled to thesecond strut, the second paddle comprising a second inner surfaceadapted to face the limb of the patient, and a strap system configuredto interface with the first and second paddles for tightening around thelimb. The first inner surface and second inner surface may include aplurality of protrusions, and the plurality of protrusions may beconfigured to minimize sliding of the first and second paddles withrespect to the limb or with respect to a cast applied to the limb. Thefootbed may include a first support layer located on the footbed, thefirst support layer including a first aperture, and a second supportlayer located on the first support layer, the second support layercomprising a second aperture larger than the first aperture and at leastpartially overlapping the first aperture. The footbed may furtherinclude a third support layer located on the second support layer, thethird support layer including a third aperture larger than the first andsecond apertures and at least partially overlapping the first and secondapertures.

An orthotic device according to embodiments of the present inventionincludes a footbed with an internal footbed and an external sole,wherein the internal footbed is substantially rigid, a first strutcoupled to the footbed, a second strut coupled to the footbed, a paddlecoupled to the first strut, the paddle comprising an inner surfaceconfigured to face a limb of a patient, a circumferential attachmentsystem configured to interface with the paddle for tightening around thelimb, wherein the inner surface includes a mechanical interlock feature,and wherein the mechanical interlock feature is configured to minimizesliding of the paddle with respect to the limb or with respect to a castapplied to the limb and to increase an area over which forces from thefirst strut are transmitted to the limb or the cast applied to the limb.

The orthotic device of the previous paragraph, wherein the paddle is afirst paddle, wherein the inner surface is a first inner surface, andwherein the mechanical interlock feature is a first mechanical interlockfeature, the orthotic device further including a second paddle coupledto the second strut, the second paddle comprising a second inner surfaceconfigured to face the limb of the patient, wherein the second innersurface includes a second mechanical interlock feature, and wherein thesecond mechanical interlock feature is configured to minimize sliding ofthe second paddle with respect to the limb or with respect to the castapplied to the limb.

The orthotic device of any of the previous two paragraphs, furtherincluding the cast applied to the limb.

The orthotic device of any of the previous three paragraphs, wherein thefirst and second mechanical interlock features are a plurality ofprotrusions, and wherein the plurality of protrusions is configured tominimize sliding of the first and second paddles with respect to thecast.

The orthotic device of any of the previous four paragraphs, wherein thecast comprises a plurality of indentations, and wherein at least someprotrusions of the plurality of protrusions are configured to protrudewithin at least some indentations of the plurality of indentations whenthe circumferential attachment system is applied to the orthotic device.

The orthotic device of any of the previous five paragraphs, wherein anangle between the first strut and the inner surface is adjustable, theorthotic device further comprising a spring element configured to biasthe inner surface away from the first strut.

The orthotic device of any of the previous six paragraphs, wherein theangle is selected to permit the paddle to accommodate calves of varyingsizes.

The orthotic device of any of the previous seven paragraphs, wherein thespring element is a leaf spring coupled to the paddle and coupled to thefirst strut.

The orthotic device of any of the previous eight paragraphs, wherein theangle is formed by an inside of a wedge-shaped pocket in the paddle.

An orthotic device according to embodiments of the present inventionincludes a footbed comprising an internal footbed and an external sole,wherein the internal footbed is substantially rigid, a first strutcoupled to the footbed, a second strut coupled to the footbed, a paddlecoupled to the first strut, the paddle comprising an inner surfaceconfigured to face a limb of a patient, a first support layer located onthe footbed, the first support layer comprising a first aperture, and asecond support layer located on the first support layer, the secondsupport layer comprising a second aperture larger than the firstaperture and at least partially overlapping the first aperture.

The orthotic device of any of the previous ten paragraphs, furtherincluding a third support layer located on the second support layer, thethird support layer comprising a third aperture larger than the firstand second apertures and at least partially overlapping the first andsecond apertures.

The orthotic device of any of the previous eleven paragraphs, whereinthe first support layer is denser than the second support layer.

The orthotic device of any of the previous twelve paragraphs, whereinthe first support layer is denser than the second support layer, andwherein the second support layer is denser than the third support layer.

The orthotic device of any of the previous thirteen paragraphs, whereinthe first support layer is adhered to the second support layer.

The orthotic device of any of the previous fourteen paragraphs, whereinthe first support layer is adhered to the second support layer, andwherein the second support layer is adhered to the third support layer.

The orthotic device of any of the previous fifteen paragraphs, whereinthe second aperture is at least partially enclosed by one or more of amesh, a thinner layer, a material that is at a lower density thanmaterial out of which the second aperture is formed, and a memory foam.

The orthotic device of any of the previous sixteen paragraphs, whereinat least a portion of the second aperture is preformed in the secondsupport layer.

The orthotic device of any of the previous seventeen paragraphs, whereinone or more other apertures are preformed in the second support layer.

The orthotic device of any of the previous eighteen paragraphs, whereinthe second support layer comprises perforations or markings for otherapertures or differently sized apertures in addition to the secondaperture.

The orthotic device of any of the previous nineteen paragraphs, whereinthe second support layer comprises perforations or markings for otherapertures or differently sized apertures in addition to the secondaperture.

The orthotic device of any of the previous twenty paragraphs, whereinthe external sole is an external rocker sole configured to permitambulation.

An orthotic device according to embodiments of the present inventionincludes a footbed comprising an internal footbed and an external rockersole, wherein the internal footbed is substantially rigid ,a first strutcoupled to the footbed, a second strut coupled to the footbed, a paddlecoupled to the first strut, the paddle comprising an inner surfaceconfigured to face a limb of a patient, and a foot support assemblylocated on the footbed, the foot support assembly molded as a singlepiece and comprising an aperture extending from a top to a bottom of thefoot support assembly, wherein the aperture is configured tocircumscribe a foot ulcer, a Charcot deformity, or a transmetatarsalamputation site, and wherein at least one dimension of the aperturedecreases along a direction from the top to the bottom of the footsupport assembly.

While multiple embodiments are disclosed, still other embodiments of thepresent invention will become apparent to those skilled in the art fromthe following detailed description, which shows and describesillustrative embodiments of the invention. Accordingly, the drawings anddetailed description are to be regarded as illustrative in nature andnot restrictive.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a perspective view of an off-weighting boot accordingto embodiments of the present invention.

FIG. 2 illustrates a perspective view of an off-weighting boot with ahardenable cast placed therein, according to embodiments of the presentinvention.

FIG. 3 illustrates a cut away perspective view of the off-weighting bootof FIG. 1.

FIG. 4 illustrates a perspective view of a multi-layer foot supportassembly according to embodiments of the present invention.

FIG. 5 illustrates a perspective view of a multi-layer foot supportassembly of according to embodiments of the present invention.

FIG. 6 illustrates a perspective view of a spring element, according toembodiments of the present invention.

FIG. 7 illustrates a paddle according to embodiments of the presentinvention.

FIG. 8 illustrates cut away side view of a paddle and a hardenable castaccording to embodiments of the present invention.

FIG. 9 illustrates a cut away side view of a paddle according toembodiments of the present invention.

FIG. 10 illustrates a front perspective view of an off-weighting bootincluding a strap attachment system, according to embodiments of thepresent invention.

FIG. 11 illustrates a front perspective view of an alternativeoff-weighting boot that may be used for a patient who has undergonetransmetatarsal amputation, according to embodiments of the presentinvention.

FIG. 12 illustrates a side elevation view of the off-weighting boot ofFIG. 11, according to embodiments of the present invention.

FIG. 13 illustrates a top plan view of the off-weighting boot of FIGS.11 and 12, according to embodiments of the present invention.

While the invention is amenable to various modifications and alternativeforms, specific embodiments have been shown by way of example in thedrawings and are described in detail below. The intention, however, isnot to limit the invention to the particular embodiments described. Onthe contrary, the invention is intended to cover all modifications,equivalents, and alternatives falling within the scope of the inventionas defined by the appended claims.

DETAILED DESCRIPTION

FIGS. 1 and 2 depict an off-weighting boot 100 according to embodimentsof the present invention. FIG. 3 illustrates a cut away view of the bootin FIG. 1. In one embodiment, the boot 100 is configured to operateover, and in conjunction with, another orthopedic device such as ahardenable cast 800. In other embodiments, the boot 100 is configured tooperate without a separate orthopedic device. In an embodiment, the boot100 includes a rigid footbed 102 to which two side struts 104 arecoupled. A support assembly 108 is coupled to the rigid footbed 102, andthe side struts 104 are coupled to paddles 106. As used herein, the term“coupled” is used in its broadest sense to refer to elements which areconnected, attached, and/or engaged, either directly or integrally orindirectly via other elements, and either permanently, temporarily, orremovably.

As illustrated in FIGS. 1-3, the outer boot 100 includes a substantiallyvertical sidewall portion 110 attached to the rigid footbed 102. Thesidewall portion 110 may have foam or rubber padding along its innersurface. In some embodiments, the rigid footbed is coupled to a curvedrocker sole 112 with a tread 114 of rubber or the like. The curvedrocker sole 112 is configured to increase stability and facilitateoff-loading of the patient's foot, according to embodiments of thepresent invention.

The support assembly 108 may include multiple layers of supportmaterial; in one embodiment illustrated in FIGS. 4 and 5, the supportassembly 108 includes an upper support layer 116, a middle support layer118, and a lower support layer 120. In other embodiments, the supportassembly 108 has only one support layer. In yet other embodiments, eachsupport layer is formed from a supportive material, such as foam orrubber. In other embodiments, the composition of support layers 116,118, 120 varies from layer to layer to take advantage of variousproperties of different materials. For example, upper support layer 116can comprise a soft or less dense material, which provides comfort but alower degree of support, while middle support layer 118 and lowersupport layer 120 may comprise a more firm or dense material, whichsupplies a higher degree of support. Various foams (open cell or closedcell foams), silicones (compressible or non-compressible),polyurethanes, and/or gels may be used to provide the sequence offirmness or durometer. In some embodiments, the lower support layer isformed of an EVA-based material having a hardness of 35-55 Shore A. Themiddle layer is also formed of an EVA-based material with a hardness of20-40 Shore A. The top layer is formed of a closed cell EVA-basedmaterial with a hardness of 20-25 Shore A, such as P-Cell® manufacturedby Acor®. The support layers 116, 118, and 120 may be fused or otherwiseattached together to facilitate easy application. The support assembly108 may also be molded of a single piece of foam material, according toembodiments of the present invention. Such a single piece molded supportassembly 108 may include one or more apertures which narrow or decreasein size from top to bottom, according to embodiments of the presentinvention. Such a single piece molded support assembly 108 may includeone kind of material, and/or may include two or more kinds or layers ofmaterials which are co-molded, for example.

As illustrated in FIG. 3, the apertures 122, 124, 126 form what may bereferred to as a “well” which receives a Charcot deformity or footulceration. A cushioning element, such as, for example, a gel-filledpacket or an air-filled packet, may be placed within or under this well,to provide additional comfort to the user, and to minimize hard surfacecontact.

In FIGS. 4 and 5, support layers 116, 118, and 120 each include asupport aperture 122, 124, and 126, respectively. In other embodiments,each support layer may have more than one support aperture or may haveno support apertures. In one embodiment, the support apertures areconfigured to circumscribe a foot sore or ulceration on the bottom of apatient's foot, so as to protect the foot sore from contact with thesupport assembly 108 or rigid footbed 102. The support apertures alsoprotect the foot sore from pressure asserted during ambulatoryactivities, according to embodiments of the present invention. In casesin which the patient has more than one foot sore, the support layers mayinclude multiple support apertures, with each aperture configured tocircumscribe a single foot sore. Alternatively, the support layers maycomprise support apertures configured to protect multiple foot sores.The footbed 102 and support layers 116, 118, 120 accommodate a Charcotdeformity to ensure that no additional trauma is imparted to the injuryduring use of the boot 100, according to embodiments of the presentinvention. These one or more support layers essentially encase theCharcot protrusion in hardened and/or semi-hardened forms to protect thedeformity from “bottoming out” on the rigid footbed 102, according toembodiments of the present invention. As such, the boot 100 may bereferred to as a “floating-type” device, which hinders “bottoming out”even for heavier patients. The support layers and support apertures mayalso be configured to address other orthopedic or medical issues, suchas bunions, plantar fasciitis, heel spurs, stress fractures, fallenarches, and the like, according to embodiments of the present invention.

In one embodiment, the support layers 116, 118, and 120 have supportapertures that vary in size to add increased support while establishinga protective cavity around the foot sore. Specifically, the supportlayer closest to the foot, for example upper support layer 116 in FIGS.4 and 5, includes an aperture 122 configured to circumscribe aparticular foot sore or a particular area of the foot. The next supportlayer, for example the middle support layer 118 in FIGS. 4 and 5,includes a support aperture 124 that is smaller in size than supportaperture 122, which enables the middle support layer to help bearambulatory pressure without putting pressure on the cast in the vicinityof the foot sore. The next support layer, for example the lower supportlayer 120, has a support aperture 126 smaller than support aperture 124,which permits the lower support layer to further bear ambulatorypressure without putting pressure on the cast in the vicinity of thefoot sore. This minimizes both ground reactive forces and shearingstress in this area. The arrows shown in FIG. 5 demonstrate that thepressure placed each layer decreases from layer 116 to layer 120. Infact, plantar pressure at the end of the lowest aperture 126 may benegligible. While in FIG. 5 arrows are only shown on the perimeter ofthe layers for clarity, in practice the pressure will be across thesurface of the support layers as well. In other embodiments, more orless than three support layers can be used to form the cavity, with eachsupport layer having support apertures of decreasing size from top tobottom. The shape of each support aperture can vary to accommodateparticular patient needs. In one embodiment, each support layer hassupport apertures with a substantially identical shape and size.

In those embodiments in which a support layer has multiple supportapertures, for example upper support layer 116, the support apertures onthe remaining support layers can be configured to match theconfiguration of the support apertures on the upper support layer. Inone embodiment, the remaining support layers can have support aperturesof decreasing size, relative to the support aperture located above them.The support assembly 108 may also utilize a support layer without anysupport apertures; that support layer is placed below at least onesupport layer having a support aperture so that the foot sore is notaggravated during ambulatory activity, according to embodiments of thepresent invention. In addition, the support apertures in the supportlayers can be configured to accommodate extra padding over the foot soreor can be configured to circumscribe a wound access window in anorthopedic device, such as a proximal flange in a foot cast. Thus, thesupport assembly 108 can comprise one or many support layers, accordingto particular patient needs, and each support layer may include none orseveral support apertures tailored to address specific medical issues.

The support assembly 108 may include support apertures 122, 124, 126which are formed by removing a portion of each respective layer 116,118, 120, according to embodiments of the present invention. Forexample, each layer may include one or more preformed or perforatedsupport aperture locations as removable pieces, which permit the medicalprofessional to decide at or during the time of treatment where tocreate the apertures. For example, the preformed or perforated supportaperture locations may correspond to the apertures 122, 124, 126 shownin FIG. 5. Other support assembly 108 systems may be used, for example asupport assembly 108 that has support apertures corresponding to atransmetatarsal amputation (TMA) wound or foot deformity on a patient'sfoot. Also, although support apertures 122, 124, 126 are described asholes, support apertures may also or instead be zones where the layermaterial or the support assembly 108 material is thinner, is of a lowerdensity, is formed of more conforming foam, and/or includes a meshportion. For example, the apertures 124 and 126 may be holes, butaperture 122 may include a thin mesh layer covering the opening, suchthat aperture 122 is not a hole per se, but rather an area that isthinner than the surrounding material, and which thus does not applysignificant pressure to the area bounded by the aperture 122, accordingto embodiments of the present invention.

According to embodiments of the present invention, the one or moresupport apertures 122, 124, 126 are formed in the shapes of ovals, withthe longest dimension of the ovals extending longitudinally from thefront to the back of the footbed 102. According to some embodiments ofthe present invention, each of the support layers 116, 118, 120 have anouter shape that substantially corresponds to an inner shape of thefootbed 102 and/or side wall 110. The support apertures 122, 124, 126may each be ovals with the same longest dimension, and differing lateraldimensions (the lateral dimensions extending in a direction betweenmedial and lateral sides of the footbed 102). For example, the supportassembly 108 includes three layers 116, 118, 120 with each layer havinga support aperture 122, 124, 126, respectively, with the supportapertures 122, 124, 126 formed in the shape of ovals with their longestdimension aligned longitudinally from the front to back of the footbed102, their longest dimensions being substantially the same, with thelowermost layer 120 having an aperture 126 with the smallest lateraldimension, the middle layer 118 having an aperture 124 with a lateraldimension larger than the lateral dimension of the aperture 126, and thetop layer 116 having an aperture 122 with a lateral dimension largerthan the lateral dimension of the apertures 126 and 124, according toembodiments of the present invention. According to embodiments of thepresent invention, the rocker sole 112, in combination with the one ormore layers 116, 118, 120, creates a concavity below the patient's footto protect, and minimize irritation of, a plantar ulceration. The topsurface of the footbed is flat and will allow for accommodation of anydeformities, according to embodiments of the present invention.

As shown in FIGS. 1-3, the side struts 104 may be riveted to the footbed102 or to the sidewall portion 110; alternatively, the side struts 104may be formed integrally with the footbed 102 or the sidewall portion110. At their other end, the side struts 104 may each be riveted to orotherwise coupled inside of a wedge-shaped cavity 556 in the strutconnector 152 of the paddle 106 (see FIG. 7), according to embodimentsof the present invention. The side strut 104 is rigidly coupled to boththe paddle 106 and the footbed 102, such that a downward force impartedonto the paddle 106 is transmitted through the side strut 104 and intothe footbed, according to embodiments of the present invention. In oneembodiment, the side struts 104 are placed so that the inner surface 105of the side struts 104 substantially parallels a patient's tibia andfibula. According to some embodiments of the present invention, the sidestruts 104 are rigidly coupled to the footbed 102 in a manner which isremovable or reversible, so as to permit the side struts 104 to beremoved from the footbed 102 or folded with respect to the footbed 102,according to embodiments of the present invention. The side struts 104may be removable easily (e.g. with the push of a button or release of aclasp), or may require the use of tools to be removable, according toembodiments of the present invention. The side struts 104 may also beconfigured to pivot with respect to the footbed 102, according toembodiments of the present invention. This releasable and/or pivotingattachment permits a rigid attachment to the footbed 102 when in the useconfiguration, with such rigid attachment permitting virtually nomovement of the strut 104 with respect to the footbed 102, according toembodiments of the present invention. As such, a strut 104 may berigidly coupled with the footbed 102 by not permitting relative movementduring use, even if such coupling is also pivotable and/or removable.

FIG. 6 illustrates a spring element 300, according to embodiments of thepresent invention. Spring element 300 includes a strut attachmentportion 328 and a paddle attachment portion 330. The strut attachmentportion 328 may include one or more apertures 334, 336 for receiving ascrew, rivet, nail, bolt, or other attachment device in order to couplethe spring element 300 with a strut 104, according to embodiments of thepresent invention. Paddle attachment portion 330 may include a hookelement 338 configured to hook onto an aperture in the paddle 106,according to embodiments of the present invention. The hook element 338may be formed by bending the spring element 300, according toembodiments of the present invention. The spring element 300 may beformed of a strong yet resilient material, according to embodiments ofthe present invention.

FIG. 7 illustrates a paddle 106 with an inner side 140, according to anembodiment of the present invention. The paddle 106 includes threepaddle sections 142, 144, and 146. Each paddle section may be curved toconform to a portion of a patient's body or orthopedic device. Eachpaddle section may be formed separately and joined together in such amanner that the paddle 106 is curved to conform to a portion of apatient's leg or orthopedic device. Alternatively, the paddle sections142, 144, and 146 may be formed integrally with each other. The paddles106 may be formed in varying sizes and/or shapes, and may be formed of athermoplastic elastomer or thermoplastic rubber or thermoplasticvulcanizate, such as Santoprene™, to promote a desirable balance offlexibility, strength, and durability, according to embodiments of thepresent invention. The inner side 140 also includes one or moreprotrusions 148, according to embodiments of the present invention. Theprotrusions 148 are cylindrically shaped; other shapes, for examplecones, hemispheres, or rectangular prisms, could be used instead of, orin combination with, cylindrical protrusions 148. In addition, theprotrusions 148 can be arranged in various patterns, only one of whichis shown as an example in FIG. 7. The protrusions 148 may be arrangedand configured to engage an orthopedic device, such as a cast, so thatthe boot 100 is more firmly secured to the orthopedic device. Inaddition, the protrusions 148 can act to transfer forces from the boot100 to the orthopedic device, which further enhances the transfer offorces through the boot 100 instead of through the patient's leg,thereby further protecting the patient, according to embodiments of thepresent invention. In some embodiments the paddle 106 and/or theprotrusions 148 are formed of rubber or of a similar material. Thepaddle may include more or fewer protrusions 148 than shown, and theprotrusions 148 may be smaller and/or larger than those shown, accordingto embodiments of the present invention.

The protrusions 148 are one type of mechanical cast interlocking featurewhich may be included on the paddles 106, according to embodiments ofthe present invention. Other mechanical cast interlocking features maybe included on the paddles 106 and/or the cast 800, to permit amechanical interlock between at least part of the paddle 106 and atleast part of the cast 800, according to embodiments of the presentinvention. For example, one or a combination of waves, ridges,protrusions, indentations, barbs, tines, hooks, spikes, grit, and/orsurface texture may be applied to the paddle 106 and/or cast 800 inorder to improve the mechanical interlock (e.g. the resistance tosliding or disengagement) between the paddle 106 and the cast 800,according to embodiments of the present invention. The mechanical castinterlocking feature or features adhere the paddles 106 to the castwhile improving distribution of the load over a larger area at thecast-paddle interface, according to embodiments of the presentinvention.

The underlying orthopedic device may be one or more orthopedic devices,for example a water-hardenable cast, as shown and/or described in U.S.Pat. No. 7,758,529, issued on Jul. 20, 2010, which is incorporated byreference herein for all purposes. For example, such hardenable castsmay include a textured outer surface, for example an outer surfacehaving repeating patterns of indentations. In such cases, the sizeand/or arrangement of the protrusions 148, which may also be referred toas nubs, may correspond with the size and/or arrangement of indentationson the outer surface of the hardenable cast. The hardenable cast mayfirst be applied to a patient and permitted to harden or tosubstantially harden, and then the boot 100 may be secured to thepatient's limb over the cast, according to embodiments of the presentinvention. For example, in FIG. 8 a portion of a hardenable cast 800 isshown. FIG. 2 also illustrates a hardenable cast 800 inserted into boot100, according to embodiments of the present invention. The cast has awaffle surface 802. The protrusions 148 are configured to secure theboot to the cast by contacting the cast within multiple wafflerecessions 804. According to embodiments of the present invention, thepaddles 106 include ten protrusions 148 per square inch, which may alsocorrespond to the density of waffle recessions 804 on the hardenablecast 800. According to other embodiments of the present invention, thedensity of protrusions 148 does not correspond with the density ofrecessions 804, but the protrusions 148 otherwise interface with, fitwithin, and/or mate engagingly with the recessions 804 so as todiscourage the paddle 106 from slipping or sliding relative to the cast800. Although a hardenable cast with a textured and/or waffle surface isshown in FIG. 2, the boot 100 may also be used with other kinds ofcasts, including hardenable casts, and including for example traditionalfiberglass casts, according to embodiments of the present invention.

As shown in FIG. 7, the paddle 106 may include one or more slots 150that extend through the paddle 106. Each slot 150 may be placed at thejunction between two paddle sections or on any single paddle section.The paddle 106 also features a strut connector 152 and a springattachment feature 154. In one embodiment, the strut connector 152 formsa wedge-shaped cavity 156 having an aperture 158 on one end of the wedgefor receiving a strut 104. The spring attachment feature 154 may be arectangular aperture formed by a lower edge 160 and surrounding edges162, 164, and 166. The lower edge 160 is longer than the width of thehook element 338 and the thickness of the lower edge 160 is less thatthe span of the hook element 338, so that the hook element 338 can clipover or otherwise engage the lower edge 160. In other embodiments, thespring attachment feature 154 includes a bar to which the hook element338 couples. In other embodiments, spring element 300 and the strutattachment feature 154 are coupled via rivets, bolts, adhesive, or othercoupling mechanisms. The paddle 106 may be formed of plastic, metal, orany other stiff, supportive material. The paddle 106 may be made of aplastic molded to include the components discussed above, according toembodiments of the present invention.

FIG. 9 illustrates a cross section of paddle 106 and a side strut 104,according to embodiments of the present invention. The top end of thestrut 104 extends into a wedge-shaped cavity 556 through aperture 158.The paddle 106 includes the inner surface 140 and an outer surface 542,according to embodiments of the present invention. The strut 104 may becoupled to the inside of the cavity 556; for example, the strut 104 maybe riveted to or glued to the inside of the cavity 556 at interface 580,according to embodiments of the present invention. The spring element300 is coupled to the strut 104 at strut attachment portion 328 (forexample through apertures 334, 336), and the hook element 338 of thepaddle attachment portion 330 hooks or clips onto the spring attachmentfeatures 154, according to embodiments of the present invention. Thestrut attachment portion 328 and paddle attachment portion 130 may eachbe substantially straight and flat sections formed integrally, with abend or an angle at location 340 between the sections (see FIG. 7),according to embodiments of the present invention.

According to some embodiments of the present invention, an angle formedbetween the inner surface 140 and the outer side 580 (taken along theview of FIG. 9) changes to accommodate legs of different sizes andshapes. The spring element biases the inner surface 140 in a directionaway from outer side 580 of the paddle 106, in a direction toward theuser, according to embodiments of the present invention. This springelement 300 encourages the protrusions 148 to remain in contact with thepatient's leg and/or an underlying orthotic device applied to thepatient's leg, for example during ambulation. According to someembodiments of the present invention, the struts 104 themselves act assprings to bias the paddle 106 against the patient's leg or cast; thismay be accomplished by, for example, forming or positioning the strutswith a slight inward bend, such that the struts 104 are temporarilyseparated to accommodate the leg and then released to press snuglyagainst the leg and/or underlying cast. In this way, the struts 104 actas leaf springs, according to embodiments of the present invention.

In one embodiment, the slots 150 in the paddle 106, as well as the rigidfootbed 102 and/or sidewall portion 110, are configured to accommodate astrap coupling system 176, as shown in FIG. 10. In one embodiment, thestrap coupling system 176 uses two footbed straps 178 and two paddlestraps 180; other embodiments may employ only one footbed strap 178and/or one paddle strap 180. Alternative embodiments may utilize morethan two footbed straps 178, more than two paddle straps 180, or acombination of multiple footbed and multiple paddle straps. In oneembodiment, the paddle straps 180 are formed of material having a hooksection and loop section, and the straps are threaded through the paddleslots 150 so that the hook section couples to the loop section, asillustrated in FIG. 10. The footbed straps 178 are formed of similarmaterial. The paddle 106 may also include patches 182 of loop materialor hook material so that the paddle straps 180 can couple to the paddle106 instead of, or in addition to, the straps themselves. The patches182 may be secured to the paddle 106 through adhesive or otherattachment mechanisms. The strap coupling system 176 may utilize otherknown mechanisms for securing the paddle straps 180 or footbed straps178, such as, for example, male/female connectors, buckles, or lockingmechanisms. The length of the footbed straps 178 and paddle straps 180used in the strap coupling system 176 may be customized for eachpatient. The paddle straps 180 can also be a disposable strap configuredto lock onto itself in a non-reversible way, such that it must be cutand replaced by a medical doctor or technician.

The strap coupling system 176 is one kind of circumferential castattachment system. Other circumferential cast attachment systems may beused to hold the boot 100 against the cast 800. For example, a rubberband or other elastic band may be used to hold the struts 104 togetheraround the cast 800 or the patient's leg. Another circumferential castattachment system may include an elastic material that is wrapped aroundthe struts 104 and the patient's leg and tied or clipped or otherwisetightened around the leg to hold the struts 104 against the cast 800 orthe patient's leg, according to embodiments of the present invention.Another circumferential cast attachment system may include a clampsystem which may be placed around the boot 100 and cast 800 in an openconfiguration, and clamped closed to secure the boot 100 against thecast 800. A clamp system may operate similarly to the clamp system of aski boot, for example. Another circumferential cast attachment systemmay include a ratchet system which permits a circumferential deviceplaced around the leg (e.g. a plastic or rubber strap) to be tightenedand/or loosened incrementally. Another circumferential cast attachmentsystem may include an outer boot or “clamshell”-type device which morefully encloses and/or covers the cast 800; such an outer boot mayinclude an inner layer of foam or the like, such that when the outerboot is tightened about the cast 800, the inner layer of foam or thelike conforms to the outer surface shape of the cast 800, therebyenhancing the mechanical engagement of the outer boot with the cast 800,according to embodiments of the present invention. Other circumferentialcast attachment systems may include a combination of two or morecircumferential cast systems, for example a combination clamp andratchet system, according to embodiments of the present invention.

The two paddles 106 may be spread apart before placing the boot system100 on the patient, and, once the boot is placed, the resiliency of theside struts 104 pushes the paddles 106 back into contact with the user'sbody or underlying orthopedic device, according to embodiments of thepresent invention. In addition, the resiliency of the side struts 104can contribute additional securing forces by pushing the paddles 106against the patient's body or orthopedic device. In one embodiment, theside struts 104 are formed of carbon graphite.

In some embodiments, footbed 102, the struts 104, and the paddles 106are formed from thermoplastics, metal, rubber, or other similarmaterials. The support layers 116, 118, and 120 may be formed of anEVA-based material secured to the footbed 102 by pressure sensitiveadhesive tape. Other embodiments use similar materials for the footbed102, such as foams, silicones, polyurethanes, and the like.

FIGS. 11-13 illustrates an alternative off-weighting boot system 100′which is configured to be used with a patient who has undergonetransmetatarsal amputation (“TMA”), according to embodiments of thepresent invention. In order to accommodate TMA patients, the footbed102′ of the boot system 100′ is similar to footbed 102, but is shorter,according to embodiments of the present invention. Footbed 102′ may alsoinclude a rocker sole 112′, similar to rocker sole 112, according toembodiments of the present invention. Also, the struts 104′ are shown asshorter than struts 104, although paddles 106′ may be similar to or thesame as paddles 106, according to embodiments of the present invention.The rigid sidewalls 110′ of footbed 102′ may be higher than sidewalls110 so as to better retain the patient's foot within the boot system100′, according to embodiments of the present invention. Also, the boot100′ may include a slightly different strap system. For example, asshown in FIGS. 11-13, the boot 100′ may include straps 111 extendingfrom the back of each side of the footbed 102′, and are configured to becriss-crossed over the patient's foot and secured to an attachmentmechanism (e.g. a ring 113) on the opposite side of the footbed 102′,according to embodiments of the present invention. This attachmentsystem helps to deter the disengagement of the patient's foot and/orcast 800 from the boot system 100′, according to embodiments of thepresent invention. Boots similar to boot 100 and/or 100′ may also beused to secure an outer boot structure to a leg or a cast for othertypes of foot deformities, in addition to or instead of TMA, accordingto embodiments of the present invention.

The footbed 102′ may receive a foot support assembly similar to or thesame as foot support assembly 108, according to embodiments of thepresent invention. According to other embodiments of the presentinvention, the footbed 102′ may instead, or may further, include ahighly foamy or conformable material lining the bottom and/or sides 110′of the footbed 102′, and configured to form to the contour's of thepatient's foot. This conformance of the boot 100′ material to thepatient's foot may be particularly helpful for retaining the boot 100′on the foot or cast 800 of TMA patients, according to embodiments of thepresent invention. Also, the paddles 106′ may function similarly topaddles 106 in that they further help to keep the boot 100′ coupled tothe cast 800 and/or the underlying limb, thereby providing a device 100′which is well-suited for use with TMA patients for a number of reasons.

Various modifications and additions can be made to the exemplaryembodiments discussed without departing from the scope of the presentinvention. For example, while the embodiments described above refer toparticular features, the scope of this invention also includesembodiments having different combinations of features and embodimentsthat do not include all of the described features. Accordingly, thescope of the present invention is intended to embrace all suchalternatives, modifications, and variations as fall within the scope ofthe claims, together with all equivalents thereof.

1. A method for treating an ulcer or injury to the plantar area of a foot of a patient, comprising: providing the patient with an orthotic device comprising: a footbed comprising an internal footbed and an external sole, wherein the internal footbed is substantially rigid; a first strut coupled to the footbed; a second strut coupled to the footbed; a paddle coupled to the first strut, the paddle comprising an inner surface configured to face a limb of a patient; a circumferential attachment system configured to interface with the paddle for tightening around the limb, wherein the inner surface comprises a mechanical interlock feature, and wherein the mechanical interlock feature is configured to minimize sliding of the paddle with respect to the limb or with respect to a cast applied to the limb and to increase an area over which forces from the first strut are transmitted to the limb or the cast applied to the limb.
 2. The method of claim 1, wherein the paddle is a first paddle, wherein the inner surface is a first inner surface, and wherein the mechanical interlock feature is a first mechanical interlock feature, the orthotic device further comprising: a second paddle coupled to the second strut, the second paddle comprising a second inner surface configured to face the limb of the patient, wherein the second inner surface comprises a second mechanical interlock feature, and wherein the second mechanical interlock feature is configured to minimize sliding of the second paddle with respect to the limb or with respect to the cast applied to the limb.
 3. The method of claim 2, wherein the first and second mechanical interlock features are a plurality of protrusions, and wherein the plurality of protrusions is configured to minimize sliding of the first and second paddies with respect to the cast.
 4. The method of claim 1, wherein an angle between the first strut and the inner surface is adjustable, the orthotic device further comprising a spring element configured to bias the inner surface away from the first strut.
 5. The method of claim 4, wherein the angle is selected to permit the paddle to accommodate calves of varying sizes.
 6. The method of claim 4, wherein the spring element is a leaf spring coupled to the paddle and coupled to the first strut.
 7. The method of claim 4, wherein the angle is formed by an inside of a wedge-shaped pocket in the paddle.
 8. A method for treating an ulcer or injury to the plantar area of a foot of a patient, comprising: providing the patient with an orthotic device comprising: a footbed comprising an internal footbed and an external sole, wherein the internal footbed is substantially rigid; a first strut coupled to the footbed; a second strut coupled to the footbed; a paddle coupled to the first strut, the paddle comprising an inner surface configured to face a limb of a patient; a first support layer located on the footbed, the first support layer comprising a first aperture; and a second support layer located on the first support layer, the second support layer comprising a second aperture larger than the first aperture and at least partially overlapping the first aperture.
 9. The method of claim 8, further comprising: a third support layer located on the second support layer, the third support layer comprising a third aperture larger than the first and second apertures and at least partially overlapping the first and second apertures.
 10. The method of claim 8, wherein the first support layer is denser than the second support layer.
 11. The method of claim 9, wherein the first support layer is denser than the second support layer, and wherein the second support layer is denser than the third support layer.
 12. The method of claim 8, wherein the first support layer is adhered to the second support layer.
 13. The method of claim 9, wherein the first support layer is adhered to the second support layer, and wherein the second support layer is adhered to the third support layer.
 14. The method of claim 8, wherein the second aperture is at least partially enclosed by one or more of a mesh, a thinner layer, a material that is at a lower density than material out of which the second aperture is formed, and a memory foam.
 15. The method of claim 8, wherein at least a portion of the second aperture is preformed in the second support layer.
 16. The method of claim 15, wherein one or more other apertures are preformed in the second support layer.
 17. The method of claim 8, wherein the second support layer comprises perforations or markings for other apertures or differently sized apertures in addition to the second aperture.
 18. The method of claim 8, wherein the second support layer comprises perforations or markings for other apertures or differently sized apertures in addition to the second aperture.
 19. The method of claim 8, wherein the external sole is an external rocker sole configured to permit ambulation. 